The Rise of Tandem Perovskite Light‐Emitting Diode

Abstract In 2024, tandem perovskite light‐emitting diodes (tandem‐PLEDs) achieved a breakthrough external quantum efficiency of 43.42%, with an organic electroluminescence (EL) unit stacked atop a perovskite EL unit, surpassing the previous single‐junction perovskite LEDs. This innovative design enables a higher brightness at lower currents, enhancing the longevity and efficiency of the tandem‐PLEDs. Additionally, the tandem‐PLEDs can also be fabricated by combining a perovskite EL unit with a perovskite quantum dot unit. In this perspective, the key advancements in tandem‐PLEDs are highlighted, focusing on the development of perovskite‐organic materials, perovskite‐perovskite quantum dots, and the design principles for obtaining efficient and stable charge generation layers. But more importantly, the challenges and solutions are discussed in fabricating all‐perovskite tandem LEDs using strongly polar solvents that have yet to be reported nowadays. This comprehensive guide aims to support researchers in advancing the practical deployment of tandem‐PLED technology.